package com.hmdp.utils;

import org.springframework.data.redis.core.StringRedisTemplate;
import org.springframework.stereotype.Component;

import javax.annotation.Resource;
import java.time.LocalDateTime;
import java.time.ZoneOffset;
import java.time.format.DateTimeFormatter;

@Component
public class RedisIdWorker {
    /**
     * 开始时间戳
     */
    private static final long BEGIN_TIMESTAMP = LocalDateTime.of(2022, 1, 1, 0, 0, 0).toEpochSecond(ZoneOffset.UTC);
    /**
     * 序列号的位数
     */
    private static final int COUNT_BITS = 32;
    @Resource
    private StringRedisTemplate stringRedisTemplate;//也可以用构造函数注入
    public long nextId(String keyPrefix){
        // 1.生成时间戳
        LocalDateTime now = LocalDateTime.now();
        long nowSecond = now.toEpochSecond(ZoneOffset.UTC);
        long timeStamp = nowSecond - BEGIN_TIMESTAMP;

        // 2.生成序列号
        // 2.1获取当前日期，精确到天
        // 2.2自增长
        String date = now.format(DateTimeFormatter.ofPattern("yyyy:MM:dd"));
        long count = stringRedisTemplate.opsForValue().increment("icr:"+keyPrefix+":"+date);

        // 3.拼接并返回
        return timeStamp << COUNT_BITS | count;
    }

    public static void main(String[] args) {
        LocalDateTime time = LocalDateTime.of(2022, 1, 1, 0, 0, 0);
        long second = time.toEpochSecond(ZoneOffset.UTC);
        System.out.println("second = "+second);
    }
}
